Interestingly I had an e-tron loaner while mine had gone in a couple of months ago. It was on 20s and I had a blow-out!
Thankfully it was low-speed (30ish) but the guy behind me pulled over to say I had done nothing wrong and literally just blew out. It was however on the inner wall (facing the under carriage ) and not the outside wall so while I knew it blew out, I only realised how bad (5 inch+ gash) when it was lifted up.
BUT I am unsure if this was alloy related or if a previous driver went over something and caused it.